the effect of ox-ldl and platelets on macrophages, m2 macrophage polarization, and foam cell formation

Background: the accumulation of oxidized ldl (ox-ldl) in macrophages in association with platelet activity leads to the formation of foam cells, which play a key role in the pathophysiology of atherosclerosis and coronary artery diseases (cad). here, in this study, we aimed to investigate the simultaneous effect of ox-ldl and platelets on foam cell formation, as well as modification in cell markers. methods: first, the u937, a human monocytic cell line,  was cultured in rpmi-1640. then, isolated platelets were co-cultured with the u937 and exposed to ox-ldl (80 µg/ml) to evaluate the impact of ox-ldl on foam cell formation using oil red o (oro) staining. also, the expression of foam cells’ surface markers and cd36, abca1, sr-b1, acat1, and lxrα genes, which are involved in macrophage metabolism and ox-ldl uptake, was measured by flow cytometry and real-time pcr, respectively. results: our findings suggest that platelets promoted foam cell formation (oro-positive cells), accompanied by a higher level of cd163+ m2 macrophages. furthermore, the expression of cd36, abca1, sr-b1, acat1, and lxrα genes, which are implicated in cholesterol accumulation in macrophages, was significantly upregulated in the ox-ldl+ platelets group compared to the control (p < 0.05). moreover, the up-regulation of cd36, abca1, and sr-b1 genes in the ox-ldl+ platelets group was more accentuated compared to the ox-ldl group (p < 0.05).conclusions: owing to the positive effector role of platelets in the formation of foam cells and cd163+ cells, it could be assumed that platelets play a dual role in the development of these cells.